More information is coming out about the operation to arrest of a senior Taleban official in Afghanistan thought to be behind an attack which killed two Kiwi troops.

Lance-Corporals Pralli Durrer and Rory Malone died and six other New Zealanders were injured during the attack in northeast Bamiyan province on August 4. Two members of the Afghan special police and 11 others were also injured.

Three more New Zealand soldiers died in another attack two weeks later.

The man, described as a "senior Taleban weapons dealer", was captured early Sunday morning (local time) in an operation carried out by US and Afghan forces.

"It was a joint operation involving Afghan special operation unit members and coalition forces," said Isaf spokesman Major Martyn Crichton.

The arrest was conducted in Baghlan province where Hungarian forces work alongside the local Afghan troops.

The detained man was the third-highest ranking Taleban official in the district, Crichton said.

"He is a high-ranking member of the Taleban network that is responsible for the attack on New Zealand forces on August 4."

He also had ties to the senior leadership of the provincial Taleban grouping.

"Locally, certainly, he's a major figure."

For security reasons, Crichton was not able to say how many people were involved in the mission, nor the planning that went into it.

He did confirm that Isaf forces were confronted by insurgents as they approached the area where the weapons dealer was.

One armed insurgent was killed during the operation.

"The information that I have doesn't suggest that the insurgent was actually able to fire on the coalition forces but he was clearly armed and had intent to do so.

"They shot him before he was able to shoot them."

No coalition or Afghan members were injured.

Crichton said he did not want to overstate the overall importance of the operation.

"But clearly it's taken out a significant Taleban leader in the province."

Isaf forces were hoping the captured man would be able to provide them with more information about the attack that killed the two New Zealand soldiers.

The official was being detained and would face a trial.

Major Adam Wojack, a spokesperson for the US-led coalition in Afghanistan, said the operation that led to the arrest followed a big surveillance effort.

"There was a lot of surveillance of organisations, Taleban enemy organisations, insurgent organisations, in that area following the attacks, in part because Bamiyan had been so quiet for so long and these attacks were just so out of the ordinary," Wojack told Radio NZ.

Wojack said so far it had only been possible to connect the Taleban leader with the August 4 attack.

Once more analysis was done it would be known if the official detained and the organisation involved were behind the later attack.

The detention of the Taleban leader, as was the case any time such a person was caught, meant there was the potential for learning more about the network he was part of, Wojack said.

"That's a real key clue into unlocking whatever's going on in Bamiyan."

CAPTURE 'A RELIEF'

The grandfather of slain Kiwi soldier Pralli Durrer says the capture came as a "relief" for the family.

Jack Durrer said the news this morning came as a "surprise".

"I knew they were looking for him … It was a relief to hear. It's good they found someone that was behind it, but he's not the only one. He can't have done everything by himself," he said.

Durrer said the announcement would also provide some relief to the New Zealand troops in Afghanistan.

The man's capture meant there was one less bomb-maker, "one less danger" for the Kiwi troops, he said.

Durrer said he was not "seeking blood for blood", simply justice for his grandson's death through the Afghan courts.

KIWI TROOPS NOT INVOLVED IN ARREST

Prime Minister John Key said New Zealand troops were not involved in the arrest.

However, he couldn't rule out whether Kiwi logistics people were involved.

"They've been certainly working on trying to gather information, for exactly this reason because you need this information, you need the specific knowledge before you can actually go in and undertake these missions," he told TVNZ's Breakfast programme.

"They have arrested a senior figure, that's really good news, and that person is now in detention. Outside that I really don't have a lot of details."

"In terms of boots on the ground going in to undertake the mission; it wasn't our people," Key said.

The Government early this month dispatched four SAS logistics officers back to Afghanistan specifically to gather intelligence for a retribution attack on insurgents who killed the five New Zealanders.

At the time, Key said their mission was to collect evidence to so that a legal case could be built.

"For a court of law, you have to be able to prove you understand whose there why and where."

He was clear that they were not combat troops and said United States special forces would likely carry out the actual arrest.

"They will work with those logistical teams and that makes sense for us to do that; if we understand good intelligence on them then we understand how best to protect ourselves."